Earmuff user interface



FIG. 1 is a front perspective view of an earmuff user interface, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a side elevation view thereof;

FIG. 5 is an opposite side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines shown in the drawings are only provided to illustrate the environment of the design, and form no part of the claimed design. 

CLAIM The ornamental design for an earmuff user interface, as shown and described. 